An especially suitable way to market semisolid materials such as ice cream or a similar food is to store the food material in a cylindrical paperboard or plastic tube from which the material may be dispensed. Dispensing of the food material occurs by a piston or plunger slidably and sealably mounted within the tube and moved through the tube thereby forcing the food material therein out the other end of the tube. A desired amount of the food material may be exposed from the tube and consumed while the remainder of the food material is contained in the tube until it is desired to expose the same.
It is highly desirable to have the container produced at a very low cost, while providing durability and simplification in assembling and filling the container. It is difficult to have a durable container that is simple to assemble while being able to hold the desired material. If it is desired to make a very tight fit, the assembly becomes more difficult. If it is desired to loosen the fit, in order to make assembly easier, the holding of the material and the functioning of the device is infringed. Accordingly, balancing the problems relating to ease of assembly with ease of the dispensing are contrary forces, which must be compromised in order to obtain an effective dispensing mechanism, while at the same time achieving the required seal for such work.
A tpical prior art device had a cardboard piston with a wooden stick. This can be a problem. Sometimes the stick can penetrate the food material without pushing the food material out of the tube. At other times the cardboard seal between the tube and the piston is insufficient to support the same in a proper fashion. Accordingly, the advantages of having the condiments stored in this manner are mitigated by the defective part of the piston.
The three part container resulting from the cylinder and a two part piston is also a problem for assembly. Such an extra part involved in assembly adds to the cost of the container. But without the three-piece function, positioning for assembly of the container becomes critical. Accounting for that criticality is also costly. If the assembly can be simply accomplished by a simple structure with only two pieces to assemble, that is the cylinder and a one piece piston, great advantages are obtained.